Tag Archive: interaction

In some cases, the manipulated parameter of one control loop can impact the controlled parameter of another control loop as illustrated below. To allow both loops to operate in automatic mode, loop interaction is most often addressed by simply detuning one of the control loops by reducing the proportional gain. The valve (or another final …

At Emerson Exchange, 2011, I had the pleasure of working with Eric Chen, Research Associate, Pickle Research Center, University of Texas at Austin SRP and Willy Wojsznis, Senior Technologist, Emerson Process Management, to host a workshop that addresses commissioning of a skid process that is characterized by a high degree of process interaction. The size …

The process response to a change in disturbance or manipulated input is often the result of many mechanisms working together and interacting: heat transfer, momentum, inertia, air capacitance in an actuator, and so on. The combined effect of these different mechanisms constitutes a higher order process response. However, response of a self-regulating process often closely …

In a previous blog, I addressed some of the challenges of commissioning a multiple input/multiple output (MIMO) process that is characterized by process interaction. Also, in Chapter 12 of Control Loop Foundation – Batch and Continuous Processes we address the special considerations associated with tuning an interactive process. In such a process, each manipulated input may impact …

In many applications, the process equipment is characterized as having multiple manipulated inputs. This type of equipment configuration is often referred to as a multiple input/multiple output process. The process control consists of multiple PID blocks where a process output and process input pair are associated with each PID. The challenge in designing and commissioning …

Single-loop and multi-loop control may be used to address a wide variety of control requirements. However, if a process is characterized by extremely long process delays or by a high degree of process interaction, then other control techniques may be required. In Chapter 16 of Control Loop Foundation – Batch and Continuous Processes, pulp bleaching …

Aggressive action by one loop can upset another loop while attempting fast tight control. The most common example involves loops sharing a common utility or raw material resource, often in piping branches off of a header. The enhanced PID for wireless (PIDPlus) can eliminate the limit cycles that would spread throughout the system. The addition …